Oil and Gas at Your Door? (2005 Edition) - Earthworks

Oil and Gas Development and Impacts
Spills of oil may come from leaking tanks, leaking flowlines, valves, joints, or gauges. 136 Other
chemicals used during the production stage (e.g., solvents, workover fluids) may be spilled due
to human error. Spilled oil and chemicals may contaminate soils, groundwater and surface
watercourses.
Waste Management
• Open pits used to store wastes pose a health threat to livestock and wildlife. The wastes
often contain hydrocarbons, and seepages from waste pits may contaminate soils, groundwater
and surface watercourses. If open pits are used, they should be lined, with a leak
detection system, to prevent seepages. And the pits should be fenced-in, and nets or other
devices installed to prevent birds and wildlife from coming in contact with the wastes.
• In Wyoming, citizen complaints forced the
U.S. Environmental Protection Agency to
conduct studies into potential contamination
of their drinking water wells. Studies
revealed that wastes from an oil field service
area and an unlined waste pond at a
natural gas processing facility had seeped
into the ground and contaminated the
drinking water wells with volatile halogenated
hydrocarbons. The site was
declared a Superfund site in 1990.
Residents were provided with alternative
sources of drinking water (they were
hooked up to the nearest municipal drinking
water system), and the companies
FIGURE I-21. TORN LINER ON AN OPEN PIT.
involved were required to remove and
treat the soil, and pump and treat the contaminated
groundwater. 137
• Many materials used during maintenance procedures, such as solvents used for cleaning,
are classified as hazardous wastes after they are used. Non-hazardous alternatives, which
are safer for the environment and present fewer regulatory concerns for the company, are
available. Substitutes include: citrus-based cleaning compounds or steam instead of hazardous
solvents; a high flash point Varsol to replace the solvent Varsol (also called petroleum
spirits or Stoddard solvent) to reduce this solvent’s ignitability hazardous waste characteristic;
and water-based paints instead of solvent-based paints, which reduces or eliminates
the need for solvents and thinners. 138
4. SITE ABANDONMENT
When a well is no longer economic to operate, it is abandoned. When an oil or gas well is abandoned
it should be plugged or converted into an injection well, and the site should be reclaimed.
Sometimes a well will appear to be abandoned when in reality it is simply experiencing a temporary
halt in production. For temporary work stoppages, the well will be shut in, which is accomplished
by closing the valves at the wellhead. During this period, the well is considered to be idle.
Wells may be idle for a few days, for example, to conduct well workovers or install new pipeline
connections; or wells may be idle for a much longer duration, for example, if there is a downturn
in the global market for oil or gas. If production is still technically viable, it is much more desirable
to shut in a well rather than plug it because once the well is permanently plugged and abandoned
it is highly impractical to re-access any remaining oil or gas in the reservoir. 139
I-28